The less transient writings among mine!

This page holds together a number of links to some of the posts/notes/codes which I have come to write over the years, whether at this blog, at iMechanica, or elsewhere. As to my published papers, I plan to make them available soon.

The links are grouped together in different sections of the following headings:

  1. The two most important posts I ever made []
  2. My further thoughts/notings on diffusion []
  3. CFD code snippets in Python []
  4. The roots of the concept: “space” []
  5. Physical referents of certain mathematical concepts []
  6. Physical referents of ideas like locality, and the instantaneous action at a distance []
  7. Book reviews []
  8. Micro-level water resources engineering []
  9. Academia []
  10. Ancient Indian wisdom; philosophy of mind; spirituality []
  11. Miscellaneous (mechanics-related topics) []
  12. Miscellaneous (other topics) []

Often times, I also note some comments which I occur to me today, when I look back on these posts/papers from a distance of years, in some cases, after 10+ years!

07 August 2018, Pune


1. The two most important posts I ever made:


“QM: A couple of defensible statements. Also, a bit on their implications for the QC.”

Published at this blog: [^]. Its importance is self-explanatory. Perhaps the most ambitious one of my efforts. Still, a work in progress. Stay tuned in the “more transient” page for the further progress on this count.


“Stress or strain: which one is more fundamental?”

Published at iMechanica: [^]. This is the second most-read post at iMechanica—and, as far as posts on the theoretical topics are concerned, it is the most-read post—from among some 20,000+ threads at that forum!

iMechanica helped me gain a certain visibility, even acceptability as a peer. And it all began mostly with this post. … My more recent take on this post is here: [^].

(Back to the list of sections on this page [] )


2. My further thoughts/notings on diffusion:

If you ask me the one result I am most proud of, then I will have to say the ideas explored in my paper on diffusion.

Here are a few posts, published at this blog on this topic, tracing some of the thoughts which occurred to me after publishing my conference paper.


“A little more on my research on the diffusion equation”

The papers I ran into. Useful references for the topic. [^]


“Transient diffusion with compact support throughout—not just initially”

Here I cover a question I asked at Math StackExchange [^]. It remains an open question till date. (I have resolved it in my mind, but not published the findings anywhere.)


“There’s something wrong about the diffusion equation—but what exactly is it?”

In this post, I re-explain some parts the argument from my paper. Also, I cite further references. [^]

(Back to the list of sections on this page [] )


3. CFD code snippets in Python:

A series of posts published here. All carry Python scripts (that work!). They together cover some part of the material that I used while teaching CFD at the UG level, at the GHRCEM, Wagholi, Pune:

  1. 1D transient conduction, FTCS, Dirichlet BCs: [^]
  2. Transients in the Couette flow, Crank-Nicolson scheme: [^]
  3. First-order wave equation, first-order upwind scheme: [^]

“A small utility for blockMesh”

Published here [^]. It implements a small little but neat idea of a metadata file for the blockMesh utility of OpenFOAM.

It can be improved a lot, and I don’t mean just XML-izing it. I mean some really useful additions to the functionality. Let me know if any one is interested in a joint research paper. (Must be able to code in Python.)

(Back to the list of sections on this page [] )


4. The roots of the concept: space

I trace the meaning of the concept of space via a series of posts which I published at this blog. It’s rather epistemological in nature. Also, rather loosely written. But it carries several new ideas that are not found anywhere else:

  1. Getting going about “space”: [^]. Extension and location are the two physically existing and perceptually evident attributes which lie at the base of the concept of space.
  2. Shaping up space: [^]. How extension is measured. Shape as a measure of extension.
  3. Putting context of space in place: [^]. The idea of a place is not given in the perceptual field, but is grasped at the conceptual level. An object in motion can have a definite place but it has no location. The geometrical point as a limiting value of small sizes.

4. Physical referents of certain mathematical concepts:


“Is the physical universe infinite?”

A post published here [^]. I loosely discuss the epistemological nature of the problem.


“Why do physicists use infinity?”

A post published here: [^]. Essentially, they use the concept as a means of abstraction. I show in detail how.


“What do physicists mean by ‘multidimensional’ physical reality?”

A post published here: [^]. Essentially, the idea concerns a law concerning how the quantitative measures of certain characteristics (of physical objects) combine together. … They do so, via the cosine-projection law.


“Why is the physical space 3-dimensional?”

Published at this blog: [^]. I take a leisurely walk into one of the axioms of space. (Yes, that’s what I do, but you wouldn’t have ever believed that mathematics axioms could be grasped that easily.)


“My small contribution towards the controversies surrounding the important question of “1, 2, 3, …””

A post published here: [^]. By the time I wrote it, my understanding (as seen in the above essays) had improved a lot. In particular, here, I directly come to asserting that sizes exist metaphysically even if numbers don’t. I need to update this post and convert it into a PDF article. TBD. [sigh!]


“How many numbers are there in the real number system?”

A PDF note [^] and a loosely written post about it [^].


“The fundamental physical bases of the WR Approach (and, consequently, of FEM) in general”

A post published here [^]. To the best of my knowledge, I was the first to seek a physical meaning for the method of weighted residuals—the method at the base of FEM, the most widely used simulation method. The question occurred to me while I was teaching a course on FEM at COEP. It still remains an open question.


“”Think It Over, and Then, Program!”… And, also, a bit on the calculus of variations…”

A post published here: [^]. An informed rant, interspersed with a good solution. The approach I advocate actually works for me.


“Some aspects of modeling with continua in physics and engineering sciences”

A post published here: [^]. It provides an evidence of my struggle towards grasping a couple of ideas that so many people never come to grasp explicitly or in all generality. The two ideas are: (i) that a continuum is infinitely divisible (see also the post here [^]); and (ii) the novel point (towards which here I was struggling), viz., that the continuum also supports infinite separability of material points if they lie on different sides of a singular surface in the solution.

(Back to the list of sections on this page [] )


6. Physical referents of ideas like locality, and the instantaneous action at a distance:

A series of posts on a foundational issue from physics, published at this blog. Extraordinarily important,  from the view point of concepts like: instantaneous action at a distance (IAD), locality, causality, etc. The discussion here shows how many apparently nonsense ideas (like IAD) can also make sense when their discussion is anchored in a right way into the perceptual reality.

  1. Introducing a very foundational issue of physics (and of maths): [^]
  2. The One vs. the Many: [^]
  3. Some of the implications of the “Many Objects” idea…: [^]
  4. Some of the implications of the “One Object” idea…: [^]
  5. Relating the One with the Many: [^]

(Back to the list of sections on this page [] )


7. Book reviews:


“David Harriman’s “The Logical Leap”: grade “A” (but a qualified one, not straight)”

A post published here: [^]. A great book on the theory of induction. Yet [in my today’s words] Harriman misses the point that sizes/magnitudes and their measures (like numbers/quantitative variables) are two different things. The former exist metaphysically, the latter are only man-conceived. His errors seem to spring from treating the two as identical.


“One more recommendation for your holiday reading: Manjit Kumar’s “Quantum””

A post published here: [^].


“A nice little book on mathematics for biologists—and for the rest of us!”

A post published here: [^].


“A little about “Speakable and Unspeakable in Quantum Mechanics””

A post published here, way back in August, 2009 (about 9 years ago, before even my PhD defence took place). [^]. I today (on 07 August 2018) re-read it, and was startled to find that despite all the changes in my positions since then, how, on some crucial essentials, I have always remained so consistent!

(Back to the list of sections on this page [] )


8. Micro-level water-resources engineering:

A series of posts published here:

  1. My the-then loose thoughts while launching a research in this topic. [^].
  2. A collection of links to portals and other references: [^]
  3. A discussion of the geology of Maharashtra and its implications: [^]
  4. A Python script to estimate the volume of water stored in a toy model of a series of check-dams: [^]
  5. A discussion of the runoff calculations, and a Python script for the same: [^]
  6. The importance of evaporation: [^]

(Back to the list of sections on this page [] )


9. Academia:


“Are the recent CS graduates from India that bad?”

My loose thoughts on the topic, published at this blog: [^]


“They don’t even touch a good text-book!”

A post published here: [^]. I demonstrate (with an Excel worksheet) how vacuous professors’ expectations are.


“M Tech (Mech.) admissions—an open letter to COEP authorities”

A post published here, in June 2008: [^]. It was expected that it would fall on deaf ears. It did.

(Back to the list of sections on this page [] )


10. Philosophy of mind; ancient Indian wisdom; spirituality:


“Am I an Objectivist?”

Published at this blog: [^]


“What is the soul?”

Published at this blog: [^]


“(A)theism, God, and Soul”

Published at this blog: [^]. Also has some commentary on the etymology of some Sanskrit terms like “divya”.


“Translation seen as an exacting process”

Published at this blog: [^]. I show, with a concrete example, how bad philosophical positions or a poor epistemology can subtly distort the usual English translations of the ancient Sanskrit verses. I take the example of the famous “tamaso maa jyotirgamay.”


“punashcha hari: om”

Published at this blog: [^]. I again look at the meaning of the Sanskrit phrase in the title.

(Back to the list of sections on this page [] )


11. Miscellaneous (mechanics-related topics):


“Yo—2: The eminent bumpiness of the “non-analytic” mathematics”

Published at this blog [^]. Most engineers would not be able to name even just one non-analytic function. Here, I discuss one example well known to the physics and maths people.


“MWR for the first- and third-order differential equations”

An open question posted at iMechanica: [^].

Also see another, related post (mentioned above), here [^]. As far as I know, this second question, too, remains open even as of today.


“When will a stiffness matrix become non-symmetric?”

My answer and further discussion regarding this question at iMechanica: [^] and [^]


“Those were not waves: A bit historical re. Huygens’ principle”

A post published at iMechanica: [^]


“FEM is not a local method (and it isn’t global either)”

A post published at iMechanica: [^]. Also, at this blog [^].


“Are linear and angular momenta interconvertible?”

A post published at iMechanica: [^]. Also see another post, published here: [^]


“Conservation of angular momentum isn’t [very] fundamental!”

A post published here; refers to a post by Chad Orzel: [^]


“A note on stereology”

A post published at iMechanica: [^]


“About Newton’s laws”

A comment posted at a thread at iMechanica: [^]


On “Causality”

A comment I initially made at Roger Schlafly’s blog, and then published here [^]


“An interesting problem from the classical mechanics of vibrations”

A post published here [^]

(Back to the list of sections on this page [] )


12. Miscellaneous (other topics):


“An idea on visualization of cultural contexts”

A post published here, in August 2008: [^]. The idea has since then come to be followed in several YouTube video’s etc. (I didn’t have the money to file for a patent.)


 

 

 


Page History:

  • First published: 06 August 2018, 15:51 IST
  • Additions made: 07 August 2018

 

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